Outboard motor choke and priming means



Nov. 29, 1949 G. w. MARTIN 2,439,494

OUTBOARD MOTOR CHOKE AND PRIMING MEANS Filed Feb. 1, 1946 5 Sheets-Sheet 1 "Zulu! WU,

Nov. 29, 1949 s. w. MARTIN 2,489,494

OUTBOARD MOTOR CHOKE AND PRIMING MEANS Filed Feb. 1, 1946 3 Sheets-Sheet 2 jnuenz'ors 690w eZMJV/arizn -v p 45/ JMMW. law/fl g g Nov. 29, 1949 e. w. MARTIN 2,489,494

OUTBOARD MDTOR CHOKE AND PRIMING MEANS I Filed Feb. 1, 1946 s Sheets-Sheet s Jnuenim 660 298 ZM/Wczrzi Ln.

Patented Nov. 29, 1949 UNITED STATES PATENT OFFICE OUTBOARD MOTOR CHOKE AND PRIMING MEANS This invention relates to carburetors, and has movement of the choke' valve from its fully to do with choke and priming means particularly-p suitable for use with outboard motor units.

Outboard motor units ordinarily comprise an internal combustion engine having an associated carburetor for supplying to the engine or motor a proper fuel-air mixture. Carburetors commonly have a float bowl or chamber to which the liquid fuel is supplied under pressure, admission of fuel to the float chamber by a float therein for maintaining the fuel at a desired level, under normal operating conditions. To facilitate starting of the motor, particularly when it is cold, means is provided for choking the engine and priming the carburetor.

To that end, the carburetor is provided with the usual fuel-air passage, communicating with the float chamber, such passage being controlled by a choke valve, as well as'the usual throttle valve,

means being provided whereby the float may be vw depressed for admitting additional fuel to the float chamber and thereby raising the fuel-level therein above normal, for flooding or priming the carburetor to assure adequate supply of fuel to the fuel-air passage sufficient to start the motor 9 when cold.

In some outboard motor units the carburetor is placed in an exposed location and priming is accomplished by depressing with the finger. a

plunger located above the float in the carburetor, 3Q

choking being accomplished by turning a knob or handle which operates the chokevalve. It is becoming increasingly the practice to enclose the motor and its appurtenances, in outboard motor units, in a shroud which provides for stream- 35 lining so as to reduce wind resistance and also protects the motor and its appurtenances, including the carburetor, while also improving the appearance of the unit. In such units, the carburetor, being enclosed by the shroud, is not 49 readily accessible and cam and lever arrangements are employed for effecting the choking and priming operations. Such arrangements are ordinarily rather inflexible as to the location, outside of the shroud, of the knob or handle for operating the choke valve, which often necessitates the location of such knob or handle in an inconvenient position.

My invention is directed to carburetor choke and priming means which is highly flexible with respect to positioning of the knob or handle for operating the choke valve, so that such knob or handle may be located so as to be readily accessible, conveniently adjacent the fuel supply control valve and the highspeed regulating valve of the carburetor. I' also provide means whereby priming may be accomplished in the movement of the choke valve from its normal open or run position to substantially closed positon for starting the motor. Preferably, priming is effected by being regulated 1Q closed or choke position to a slightly open position so that, whendesired, the engine may be choked without priming. That is desirable since in, many cases priming may not be required to start the motor, as in warm weather or when the motor is not sufiiciently cold to render priming necessary for starting. On the other hand, if it is found that the motor will not start readily when the choke valve is in its choke position; movement of this valve a slight distance beyond choke position, in the same direction in which it was moved from its run position to choke posi-'- tion, effects priming to assure starting of the motor. Preferably, the priming means comprises means whereby the choke valve is automatically returned from its priming position to its choke position upon release of the manual means for operating such valve. That avoids likelihood of excessive priming and flooding of the carburetor, with possible failure of the engine to start, such as might occur if the operator left the choke valve in priming position for too long a time, or if priming occurred when the choke valve is in its choke position, in which itremains until it is moved therefrom manually by its-associated operating member. The choke and priming means of my invention is of simple and inexpensive construction; while being durable and facilitating choking and priming, or choking alone, as desired. Furtherobjectsand advan tages of my invention will appear from the detail description.

In the drawings: V

Figure 1 is a side view of an outboard motor unit embodying the choke and priming means of my invention;

Figure 2 is a plan view, of a carburetor embody-f ing the choke and priming means of my inven; tion, the motor shroud being shown fragmentarily and in section and the manifold cover being shown fragmentarily;

Figure 3 is a sectional view taken substantially on line 3-3 of Figure 2, certain parts being shown in elevation:

Figure 4 is a detail elevational view, on an enlarged scale, partly broken away and in section; of the choke valveand its shaft and the flexible member for operating the latter, thisview showing also the arm 'for operating the priming plunger and the member for connecting this arm to the shaft for turning therewith;

' Figure 5 is a sectional view, on 'an enlarged scale, taken substantially-on line 5-5 of Fig ure 4;

Figure '6 is a fragmentary front 'view, on a re duced scale, of the engine shroud and the associated carburetor valve operating members;

and

Figure I is a central vertical sectional view,

taken from front to back and on an enlarged scale, of the carburetor shown in Figure 2, certain parts being shown in elevation.

In Figure 1 I have shown an outboard motor unit Ill having an associated handle II suitably attached thereto. Unit H1 is provided at the upper end thereof with a power head I2, including an internal combustion motor and itsappurtenances, enclosed within a suitable streamlined. housing l3 including a shroud I4, this housing I 3 carrying a fuel supply tank, the power head being mounted on the upper end of a motor-support tube mounted for turning movement about a substantially vertical axis through a tubular housing l5, for steering purposes. An underwater unit: t6: is bolted or; otherwise suitably secured to: the fitting I? fixed on the lower end of themotor support tube at the lower end of housmg l. The underwater unit it comprises an intermediate housing is and a lower gear case tdcontaini-ng gearing establishing driving connection between the drive. shaft of the motor; which shaft extends downward through the motonsupportvtubeandthe'housing ill-into the gear case: t9; and the: propeller shaft on which: the propeller is' mounted; gear case- 5 9. being provided with: a downwardly extending skeg 21. Housing: i5 is: provided, at its upper end, with an outwardly extending arm 22- fixed thereto, preferablyintegral with one section thereof, this housing; being conveniently formed in twosectionssbolted together, which arm is pivotally connectedat. 23,-to-a clamping bracket 24, for tilting movement about a substantially horizontal axis; The, bracket. 24' isof generally G-shape and is provided. with clamping screws, one of which: is shown at 25, which: cooperate with the after arms of. bracket 24 for clam-ping the latter to: thesillor transom: atthe stern of a boat, as is known. It will be. understood that the outboard motor unit L0. shown in Figure: 1- is illustrative. only, and that the choke: and priming means of my instant in,- vention may be: used either with that unit. or with anyother suitable unit. InE-igure 2 I. have. shown the choke and priming means of myinvention as applied to a. carburetor 2-! which, with the motor. (not shown) isenlosed within the shroud M. The carburetor 21- is provided with a bolting flange 28. bolted to a manitold cover plate- 29 which. issuitably secured tothe motor, by bolting or in. other'suitable manner. The carburetor 27 is of known constnuction, except as to those features having to do particularly with my invention, and a brief description thereof' will: suffice; It comprises a float chamber or how].- 39 suitably secured to. an upper section 3!, with an intervening gasket 32: The liquid fuel is supplied to float chamber 3D-througha tube.- 33 under pressure due to-grav-- ity, from a fuel tank (not shown) in the upper portion of. housing l-3. A fuel supply control valve 34 is interposed in. tube; 33; stem- 35 of this: lvalve extending through the forward end of shroud I4 and having a suitable: knob 36 secured thereon: As will: beunderstood, supply' of fuel tor-the carburetormay be cut off and restored by turning valve 34 into proper position. Admis siomof fuel: to thefloat chamber 3B isregulated bya needle valve 38 under control of a float 40 pivoted at 4| in chamber 343, as is known. The float 40: and: the needle valve 38 serve normally to: maintain the fuel at a predetermined: desired level within float chamber 36, as iswell understood.

The upper.- or cover section 31 of the carburetor 21 is provided with an air-fuel passage 43, of Venturi shape, and with a tubular element or sleeve 44 depending therefrom into float chamber.- 30,. centrally thereof, float being of annular' shape, as is known. A main discharge nozzle or high speed jet 45, closed at its lower end, is threaded at its upper portion into sleeve 44. An idler tube 46 extends downward through the upper end of jet 45, this tube being open at its lower end. Tube 46 extends across passage 43 and thence upward into a lengthwise passage 4! of a rib 48- extending lengthwise of carburetor section 3|. A portion of tube within passage 4-1 enlarged at 41a and is provided with a restricted opening 49 communicating with passage 4. 11.. At its upper end tube: 46' is; provided with a screw: head 5B which threads into a boss 5| integral with rib 48L Tube 46' is further provided; at. the lower endv of the enlarged portion. 41a thereof, with a collar 52 which seats on a sealing gasket 53 surrounding this tube-at the bottom. of passage 41. Fuel is admitted from float chamber 30' to: nozzle or jet 45 adjacent the lower end thereof, through aligned port's (Figure 7) controlled: by a high speed regulating needle valve 5.5 the stem 01% which extends forwardly through shroud. M and. has secured on its outer end a knob 56: for: convenience in. adjustment of this valve; The stem of valve FIE-underlies anair bleed needle valve 51 for regulating the admission of air to passage 47; of rib 48-, the: latter being provided with-ran air'bleedopening 58,, as is known. Valve 5t is'provided with anintegral: collar 59 between which and the forward end of rib 48' a compression spring 66, disposed about the stem of valve 54 is: confined, for holding this valve in adjustment; Adjacent the rearward end of passage 43, the carburetor is provided with a throttle valve having a shaft 62' projecting to one side of the carburetor, as shown in Figure 2. The carburetor is further provided with suitably disposed openings. establishing; communication. between passage. ofv rib 48 and passage 43, at the throttle valve area thereof, as. is known. The carburet'QISO: fardescribedisv of known construction and operation andrequires no further description excent as to: those features: which have to do with my; invention.

A. choke valve 63 is: disposed in the forward or entrance end of. passage 43. Valve 53. is secured on a shaft 64' rockably mounted in the forward portion of uppersection 3!! of the. carburetor and projecting outward thereof to one side of the. carburetor body. Shaft 54 is provided at its outer end with acollar 65 fixed thereto, conveniently formed integral therewith. The end portion of shaft 64, including the collar 65, is axially bore-:l for reception of one. end portion of a flexiblemember 66 secured. therein in a suitable manner, conveniently by means of a set screw 6'1. Member 66 conveniently is formedof a length of a braided wire rope or cable of known type and is flexible throughout its length. This member extends from shaft 64,. substantially at right angles thereto, forward through the forward wall of shroud I4 and has secured on its forward end, in anysuitabl'e' manner, an. operating-knob 68,. at the outer face of shroud Hi, there. being a stop collar 69? secured onmember 66 at the inner face of the forward wall of shroud. M. It will be seen that the member 66 provides means for turning the:- choke' valve shaft 64' in either direction desired. and, due to its ready flexibility, provides simple and efiicient means whereby the knob 68 for operating the choke valve may be disposed adjacent the knobs 36 and 56, providing a'convenient assembly such that ready access to the throttle valve knob, as well as tothe knobs 36 and 56, is assured.

Choke valve shaft 64 is provided, adjacent and at the opposite sidethereof from choke valve 63, with a flat II. This .flat is disposed for contact by a spring pressed ball or plunger (not shown), the spring of which is confined between the plunger and a screw plug 12 threaded into a boss 13 projecting from'oneside of rib 48. The spring pressed plunger cooperates with the flat H for normally holding choke valve 63 in its full open or run position shown in dotted lines in Figure 2, asis known. The particular means for holding the choke valve in itsrun position is not of the essence of my invention and any other suitable means may be provided for that purpose. As noted, the choke valve 63, when the engine or motor is in operation, normally occupies its full open or run position. In order to start the motor, the choke valve 63 is turned through approximately 90, from its full open or run position to its full closed or choke position, by means of knob 68 and the flexible operating member 66.

That provides for choking the engine, for starting, as is well understood. I also provide means whereby the carburetor may be flooded for priming the engine to facilitate starting thereof, under conditions where choking alone may not be sufficient, as when the engine is quite cold, as in cold weather or unusually low temperature, as will be explained.

An arm 15 is loosely mounted at its forward end on shaft 64, at the inner face of collar 65 thereof, this arm 15 having a tab 16 struck inward therefrom. A pin 1'! is secured to shaft 64, conveniently by having a reduced portion 11a driven through shaft 64 diametrically thereof. The pin i1 is disposed to contact the upper edge of tab 15, when shaft 64 has been turned a predetermined distance in clockwise direction, as viewed in Figure 5, for turning the choke valve 63 from its normally open or run position to its substan tially closed or choke position, as will be explained more fully presently. Arm 15 is provided atits rearward end with an opening 18 which receives an upwardly ,curved hook element 19a at the lower end of wire. link 19. At its upper end link 19' is provided with a straight horizontally extending element 192) which is inserted diametrically through the upper end portion of a plunger 80 slidable through a guide tube 8! screwed at its upper end-into the top wall of upper section'iil of the carburetor, adjacent a boss 82 extendingfrom one side of rib 6.8, this boss being provided with a bore 83 extending from its under face and an. air inlet port 84 opening into bore 83, as shown. Plunger 8!! is urged upward by a compression spring 86, disposed thereabout and confined between the top wall of carburetor section 3| and a washer 8'! disposed about plunger 80, at the under face of element 190. of link [9. A cross pin 88, secured to plunger 8!! a short distance above the lower end thereof, limits the upward movement of plunger 8!! by spring 85. this plunger normally occupying its position shown in Figure 3, in which the lower rounded end of the plunger overlies the float 4B.

In order to start the motor, assuming that the choke valve is in its run position, shaft 64 is turned in clockwise direction, by means of the flexible operating member 56, as viewed in Figure 5. thus turning valve 63 in closing direction. Preferably, the pin 11 is so disposed that it con- 6 taots tab 16 of arm I5 when the choke valve 63 has been turnedinto its fully closed or choke position, or substantially so. The motor is thus choked and, if conditions are suitable, may be started. As above noted, however, under unfavorable conditions priming may be required to assure start.. ing of the motor. In such conditions, shaft 64 is turned a further distance in clockwise direction,- carrying with it the arm 15. This movement of arm 15 with shaft 64 forces the plunger 80 downward in opposition to spring 86, as will be clear from Figure 3. The plunger 80, in its downward movement, contacts float 40 and, when the choke valve 63 has been moved a slight distance beyond its choke position into prime position, in which it is cracked open a slight distance, the plunger 80 depresses float 40 into position opening the needle valve 38. That permits free flow of fuel into the float chamber 30, flooding the carburetor and thus priming the motor, in a known manner. By relating the pin 11 and tab I6 of arm I5 in the manner stated, the choke valve 63 may be moved into choke position without priming and,-.

in the continued movement of this valve in closing direction, that is, in the direction in which it is turned for closing, the plunger 80 may be depressed for priming. That is desirable in that it renders it possible either to choke without priming, or to choke and also prime, by turning the choke valve shaft in one direction, which isis'then released. Upon release of knob 68 the:

spring 86 returns choke valve 63 to its choke position. That is advantageous in that it guards against excessive priming and possible failure ofthe engine to start, such as might occur if means were not provided to assure return of the choke valve from its prime position to choke position. Conveniently, though not necessarily, a choke and primer control knob 68 is provided with an index mark 68a and the forward wall of shroud I4 is provided with a dial concentric with knob,

58 marked to indicate the angular positions thereof corresponding to the prime, choke and run positions. of the choke valve, as shown in Figure 6.

As above indicated, and as will be understood;

by those skilled in this art, changes in construction and arrangement of parts of my invention may be resorted to without departing from the field and scope thereof, and I intend to includeall such variations, as fall within the scope of the appended claims, in this application in which the preferred form onlyof my invention has been disclosed.

I claim:

1. In outboardmotor choke and priming means", a carburetor having a float chamber with a float therein and float controlled means for regulating admission of fuel to said chamber and thereby maintaining a normal fuel level therein, said carburetor also having an air-fuel passage in communication with said float chamber, a choke.

valve carried by said carburetor controlling said passage and turnableabout an axis extending transversely of said passage, a flexible operating member connected to said valve and extending substantially perpendicular tosaid axis'for open ing and closing said valve, and means whereby said float is actuated responsive to closing ofsaid' choke valve' thereby: raising the fuel level in said fioatchamber above normal.

' 2. In-outboard motor choke-and priming means, acarburetor having a float chamber with a float therein and. float controlled means for regulating admission of fuel. to said chamber and thereby maintaining a normal: fuel level therein, said carburetor also having an air-fuel passage in communication with said float chamber, a choke valve carried by said carburetor controlling said passage and turnable about an axis extending transversely of said passage, an operating member flexible throughout its length attached at one end'tc said valve and extending substantially perpendicular to said axis for opening and closing: said valve, and means connected to said valve whereby said float isactuated responsive to. closing of said choke valve thereby raising the fuel level in said float chamber above normal.

3. In outboard motor choke and priming means, a carburetor having a float chamber with a float therein and float controlled means for regulating admission of fuel to said chamber and thereby maintaining a normal fuel level therein, said carburetor also having an air-fuel passage in communication with said float chamber, a choke valve carried by said carburetor controlling said passage having a shaft projecting outward beyond said carburetor at one side thereof, an operating member flexible throughout its length secured at one end to said shaft extending substantially perpendicular thereto for turning said shaft in one direction for closing said valve and in the opposite direction for opening said valve, a plunger slidable through the top of said carburetor overlying said float having limited upward movement and normally yieldingly held raised, an arm loose on said shaft, means providing lost motion connection between said shaft and said arm effective for turning the latter with said shaft in the turning thereof in said one direction when said valve has been moved to substantially fully closed position, and connections between said arm and said plunger whereby the latter is depressed in the turning movement of said arm with said shaft in said one direction thereby depressing said float and raising the fuel level in said chamber above normal.

4. In outboard motor choke and priming means,

a carburetor having a float chamber with a float therein and float controlled means for regulating admission of fuel to said chamber and thereby maintaining a normal fuel level therein, said carburetor also having an air-fuel passage in communication with said float chamber, a choke valve carried by said carburetor controlling said passage having a shaft projecting outward beyond said carburetor at one side thereof, means for turning said shaft in one direction for closing said valve and in the opposite direction for opening said valve, a plunger slidable through the top of said carburetor overlying said float having limited upward movement and normally yieldingly held raised, an arm loose on said shaft, a member fixed to said shaft disposed to contact said arm when said valve reaches substantially fully closed position, and connections between said arm and said plunger whereby the latter is depressed in the turning movement of said arm with said shaft in said one direction beyond its position-in which said valve is fully closed thereby depressing said float and raising the fuel level in saidchamber above normal.

beyond said carburetor atoneside-thereof, means.

for turning said shaft in one direction for closing said valveand in the opposite direction for opening said valve, a plunger slidable. through the top of said carburetor overlying said float having limited upward movement and normally yieldingly held raised, an: arm loose on said shaft, a collar on said shaft at. one side of said arm, a member nxed to said shaft at the other side of said arm in cooperation with said collar restraining said arm against relative movement lengthwise of said shaft, said arm having'a-n" element disposed to be contacted by said member when said valve reaches substantial-1y fully closed position, and" connections between said arm and said plungerwhereby the latter is depressed in the turningmovement'of said arm with said shaft in said one direction thereby depressing said float and raising the fuel level in said chamber above normal.

6. In outboard motor choke and priming means.

a carburetor having a float chamber with a float therein and float controlled means for regulating admission of fuel to said chamber and therebymaintaining a normal fuel level therein, said carburetor also having an air-fuel passage in communication with said float chamber and fuel supply and highspeed regulating valves provided with forwardly projecting operating stems, a choke valve carried'by-sai'dcarburetor controlling said passage having a shaft projecting outward beyond said carburetor at'on'eside thereof, said choke valve having a run position in which it is substantially fully open and being movable therefrom in. one direction to a choke positionin which it is substantially fully closed and thence to a prime position in which it is cracked slightly' open, a flexible operating member attached: at' one end. to said shaft extending forward therefrom substantially at right angles thereto adjacent said' fuel supply and high speed regulating valve stems, and means for actuating said float. and thereby raising the fuel level in said fl'oat chamber above normal responsive to movement of said valve from its choke position to its prime position, said means comprising means for automatically returning said valve from 'prime position to choke position.

GEORGE WI MARTIN.

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